| Abstract
| - We demonstrate here that it is possible to calculate with reasonable accuracy the 17O-chemical shift for thegas-to-liquid phase change for water using density functional theory (DFT) and water clusters in which bothcluster size and cooperative hydrogen bonding are taken into account. Cooperative hydrogen bonding in ahighly structured, tetrahedrally symmetric environment results in 17O-chemical shifts sufficient to mimic thechange from monomeric water in the gas phase to that in high-pressure ice. We also show that polarizablecontinuum models (PCM) using a self-consistent reaction field (SCRF) fail to predict adequately 17O-chemicalshifts for water in the condensed liquid or solid phase, discussing this problem in terms of any solute−solvent system in which there is cooperative charge transfer. This is believed to be the first report analyzingthe 17O-chemical shielding tensor behavior in water clusters explicitly as evidenced by electron density topologyof the hydrogen bonds, NBO antibonding orbital occupancies, electric field gradients, and full electrostaticmultipole analysis for the oxygen and hydrogen atoms, thus providing an insight into the failure of thepolarizable continuum model to describe liquid water accurately.
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